1. Field of the Invention
This invention relates to methods of using nano-hybrid structured regioregular polyhexylthiophene for photoelectrochemical energy application.
2. Description of the Prior Art
In recent years, the photoelectrochemical, organic light emitting diodes, optoelectronic and solar cell devices based on conjugated polymer (p-type) and inorganic nanomaterials (n-type) have been studied due to their high electron mobility, chemical and physical stability of inorganic nanoparticles, and by large ease in fabrication and the flexibility in fabrication of larger cells at low cost. (Günes, S.; Neugebauer, H.; Sariciftci, N. S. Chem. Rev. 2007, 107, 1324-1338; Kim, J. S.; Kim, W. J.; Cho, N.; Shukla, S.; Yoon, H.; Jang, J.; Prasad, P. N.; Kim, T. D.; Lee, K. S. J. Nanosci. Nanotech. 2009, 9, 6957-6961).
The promising photo-conversion efficiencies in photovoltaic systems with PbSe, CdS, CdSe, and nanocrystals in hybrid structures with conjugated polymer in multilayered systems have been studied at large (Huynh, W.; Dittmer, J. J.; Alivisatos, A. P. Science. 2002, 295, 2425-2427; Cui, D.; Xu, J.; Zhu, T.; Paradee, G.; Ashok, S.; Gerhold, M. Appl. Phys. Lett. 2006, 88, 183111; Biju, V.; Kanemoto, R.; Matsumoto, Y.; Ishii, S.; Nakanishi, S.; Itoh, T.; Baba, Y.; Ishikawa, M. J. Phys. Chem. C. 2007, 111, 7924-7932; McCumiskey, E. J.; Chandrasekhar, N.; Taylor, C. R. Nanotechnology. 2010, 21, 225703; Abken, A. E.; Halliday, D. P.; Durose, K. J. Appl. Phys. 2009, 105, 064515). Quantum materials (e.g., polymer-nanocrystal systems) appear promising, but the use of a toxic precursor (e.g., Cd, Pb, etc.) remains a limitation to their development as an alternative to inorganic devices on a large-scale fabrication. In this context, TiO2 and ZnO nanomaterials, which are non-toxic, offer physical and chemical stability and are promising candidates for hybrid heterojunction photovoltaic cells (Boucle, J.; Chyla, S.; Shaffer, M. S. P.; Durrant, J. R.; Bradley, D. D. C.; Nelson, J. Adv. Funct. Mater. 2008, 18, 4, 622-633; Lin, Y.-Y.; Chu, T.-H.; Li, S.-S.; Chuang, C.-H.; Chang, C.-H.; Su, W.-F.; Chang, C.-P.; Chu, M.-W.; Chen, C.-W. J. Am. Chem. Soc. 2009, 131, 10, 3644-3649; Mane, R. S.; Lee, W. J.; Pathan, H. M.; Han, S.-H. J. Phys. Chem. B. 2005, 109, 24254-24259).
Recently, reports have been devoted to TiO2 nanocrystal (nc) polymer blends, mainly because of a strong incompatibility of the polar nanoparticles with common organic solvents. The use of higher hole mobility polymer such as poly(3-hexylthiophene) blends with commercial nc-TiO2 based photovoltaic device has shown external quantum efficiencies up to 15% in an overall AM1.5 solar power conversion system (Breeze, A. J.; Schlesinger, Z.; Carter, S. A.; Tillmann, H.; Horhold, H.-H. Sol. Energy Mater. Sol. Cells. 2004, 83, 263-271; Wu, M.-C.; Liao, H.-C.; Lo, H.-H.; Chen, S.; Lin, Y.-Y.; Yen, W.-C.; Zeng, T.-W.; Chen, C.-W.; Chen, Y.-F.; Sua, W.-F. Sol. Energy Mater. Sol. Cells. 2009, 93, 961-965; Shim, H. S.; Kim, J. W.; Kim, W. B. J. Nanosci Nanotechnol. 2009, 9, 4721-6). More recently, the blends of conjugated polymers and inorganic nanocrystals have offered high electron mobility with improved spectral coverage for energy applications (Stavrinadis, A.; Xu, S.; Warner, J. H.; Hutchison, J. L.; Smith, J. M.; Watt, A. R. Nanotechnology. 2009, 20, 445608; Zhao, L.; Wang, J.; Lin, Z. Front. Chem. China. 2010, 5, 33-44). The effective conduction path for charge transport in conjugated polymer blends with metal oxide or quantum dot still remains a challenge (Selmarten, D.; Jones, M.; Rumbles, G.; Yu, P.; Nedeljkovic, J.; Shaheen, S. J. Phys. Chem. B. 2005, 109, 15927-15932). The RRPHTh has a structure similar to hairy-rod polymers, which could be used for blending with inorganic particles, and form semicrystalline films with crystalline domains embedded in an amorphous matrix (Li, G.; Shrotriy, V.; Yao, Y.; Huang, J.; Yang, Y. J. Mater. Chem. 2007, 17, 3126-3140; Iovu, M. C.; Zhang, R.; Cooper, J. R.; Smilgies, D. M.; Javier, A. E.; Sheina, E. E.; Kowalewski, T.; McCullough, R. D. Macromol. Rapid Commun. 2007, 28, 1816-1824; Yazawa, K.; Inoue, Y.; Shimizu, T.; Tansho, M.; Asakaw, N. J. Phys. Chem. B. 2010, 114, 1241-1248). The high degree of crystallinity and strong inter-chain interactions in RRPHTh would lead to higher charge mobility since the carriers are no longer confined to a single chain (Loewe, R. S.; McCullough, R. D. Polym. Prepr. 1999, 40, 852-853; Ramajothi, J.; Ochiai, S.; Kojima, K.; Mizutani, T. Jpn. J. Appl. Phys. 2008, 47, 8279-8283; Reyes-Reyes, M.; Kim, K.; Carroll, D. L. Appl. Phys. Lett. 2005, 87, 8, 083506).
Recently, nanodiamond (ND) particles have gained attention due to facile surface functionalization, biocompatibility, quantum information processing, magnetotometry, novel imaging, and IR fluorescence application, and have been shown to enhance the optical and electrochemical properties of conducting polymers (Gomez, H.; Ram, M. K.; Alvi, F.; Stefanakos, E.; Kumar, A. J. Phys. Chem. C. 2010, 114, 18797-18804). These and all other referenced publications are incorporated herein by reference in their entirety. Furthermore, where a definition or use of a term in a reference, which is incorporated by reference herein is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.
Accordingly, what is needed is a nano-hybrid film having enhanced photoelectrochemical properties. However, in view of the art considered as a whole at the time the present invention was made, it was not obvious to those of ordinary skill how the art could be advanced.
While certain aspects of conventional technologies have been discussed to facilitate disclosure of the invention, Applicants in no way disclaim these technical aspects, and it is contemplated that the claimed invention may encompass one or more of the conventional technical aspects discussed herein.
The present invention may address one or more of the problems and deficiencies of the prior art discussed above. However, it is contemplated that the invention may prove useful in addressing other problems and deficiencies in a number of technical areas. Therefore, the claimed invention should not necessarily be construed as limited to addressing any of the particular problems or deficiencies discussed herein.
In this specification, where a document, act or item of knowledge is referred to or discussed, this reference or discussion is not an admission that the document, act or item of knowledge or any combination thereof was at the priority date, publicly available, known to the public, part of common general knowledge, or otherwise constitutes prior art under the applicable statutory provisions; or is known to be relevant to an attempt to solve any problem with which this specification is concerned.